Textile core with a yarn engaging groove



Nov. 8, 1966 L. H. SOWELL 3,284,023

TEXTILE CORE WITH A YARN ENGAGING GROOVE Filed Dec. 15, 1965 FIG-lINVENTOR LYLES HOWARD SOWELL.

BY MZM ATTORNEY United States Patent 3,284,023 TEXTILE CGRE WITH A YARNENGAGING GRGOVE Lyles Howard Sowell, Madison, Tenn., assignor to E. l.du Pont de Nemours and Company, Wilmington, Del, a corporation ofDelaware Filed Dec. 15, 1965, Ser. No. 513,942 4 Claims. (Cl. 242-1251)This invention relates to cores or bobbins on which yarn filaments andthe like may be wound and unwound, and more particularly, to animprovement in the construction thereof by means of which a moving yarnmay readily and effectively be caught and held by the rapidly rotatingcore to commence the initial phase of the winding operation.

In industrial operations, yarn producers customarily wind their yarns onspools or cores to form a package suitable for shipment. Modernhigh-speed production methods entail efiicient processes whereby acontinually advancing yarn is wound onto successive, rapidly rotatingbobbins or cores. The customary process sequence involves passing theyarn which is continually advancing from a source, such as a spinneret,through the intake nozzle of a sucker gun such as disclosed in MillerUS. Patent No. 2,667,964, dated February 2, 1954, frictionally engagingthe incoming yarn with a rotating core or bobbin so as to causeincipient winding of the yarn onto the core and simultaneously breakingof the yarn at a point between said nozzle and the point of frictionalengagement. Upon formation of the package, the advancing yarn is causedto pass through the sucker gun nozzle which causes the yarn to break.The package is replaced by an empty core and the sequence is repeated.The point of engaging frictional contact on the core is preferably nearone end thereof and some distance from the near edge of the normaltraverse of the yarn during package build-up. Hence, the packagecontains a transfer tail, e.g., a number of helical windings of theinitial yarn which are not covered by other yarn in the package. Thismakes possible the formation, in essence, of an endless yarn of anynumber of packages by tying the transfer tail of one package to the yarnend on the periphery of another package.

From the above process description, it can readily be appreciated thatproper core design is essential to the establishment of effectiveinitial engagement of the yarn thereon and, in a wider sense, to thepractical attainment of manufacturing objectives.

Various core designs have been tried, such as the provision of acircumferential groove in the core, adhesive substances on the face ofthe core, and various devices replaceably affixed on the core surfaces.However, such cores have failed seriously when used for catching andwinding strong, high-denier yarns at extremely high speeds of the orderof 10,000 ft./min. (3048 m./min.). These failures are attributable tothe fact that grooves and adhesives do not provide sufficient frictionalsurfaces for the high-strength yarn to be initially engaged and brokenat such high speeds, so that effective winding is impossible. Moreover,devices replaceably afiixed to the core surface, in addition to beingexpensive, are subject to relatively large centrifugal forces when thecore is rotated at very high speeds, a condition which causes thedevices to fly off the core in a very hazardous manner. To illustrate,the centrifugal force developed by a l-ounce (28.35 gm.) object on theface of a 1-inch (2.54 cm.) radius core rotating at 17,000 revolutionsper minute-an effective winding speed actually attained in accordancewith this inventionis approximately 520 lbs. (2314 newtons).

The present invention provides a core of improved design for windingyarns, threads and the like. A further provision is a textile core whichis both inexpensive and highly suitable for winding high-denier,high-strength yarns at extremely high speeds. Other provisions will beapparent from the following specification and claims.

The textile core of the present invention has, in its exterior surface,near one end, a circumferentially disposed V-shaped groove ofsubstantially uniform depth,'extending around the core in a planeperpendicular to the axis of rotation of the core, the sides of saidgroove being either convexly curved or straightly extending inward andconverging toward each other to meet or substantially meet in an acuteangle at the bottom of the groove. The groove has, along its length, aplurality of yarn traps for catching yarn in the groove and for breakingoff the lead end of the yarn. The traps are structural distortions in atleast one side of said groove, each distortion essentially comprising aprotuberance extending from one side of the groove in which it isformed, and having its locus between the bottom of the groove and apoint lying approximately of the shortest distance from said bottom to astraight line connecting the groove edges at the groove opening, aportion of the face of the protuberance substantially touching thegroove side which is opposite to it. 1

The term core as used herein refers to a supporting means for forming ayarn package, comprising an elongated rotatable body having an axis ofrotation and a curved outer surface, the periphery of the core beingcircular at transverse sections taken perpendicular to the axis of thecore. The core is normally hollow to permit its placement on a chuck orother means for rotating the yarn package which is being formed.

This invention will be more fully understood by reference to theaccompanying drawings in which: 7

FIGURE 1 is an isometric view of a core constructed in accordance withthis invention.

FIGURE 2 is a partial cross-sectional view of taken on line 22 of FIGURE1.

FIGURE 3 is a partial cross-sectional view of taken on line 33 of FIGURE1.

FIGURE 4 is a partial cross-sectional view corresponding to FIGURE 2 butshowing a modified form of the invention.

FIGURE 5 is a partial cross-sectional view corresponding to FIGURE 3 butshowing another modification of the invention.

Referring to the figures, FIGURE 1 shows core 1 con taining a groove 2,placed near the core-end 3, which has yarn traps 4. FIGURE 2 shows atypical groove or notch 2 having an opening 5 and a bottom 6. FIGURE 3shows a yarn trap, constructed in accordance with the preferredembodiment of the present invention, having an opening 5, a bottom 6, aprotuberance 7 and a depressed surface 0. FIGURE 4 shows a simple yarntrap having an opening 5, a bottom 6 and a protuberance 7. FIGURE 5shows a yarn trap having an opening 5, a bottom 6, a protuberance 7 andtwo depressed surfaces 8 and 9.

The core may be fabricated from any suitable material, paper or moldedplastic being preferred.

The term groove as used herein refers to a V-shaped notch or opening inthe core, the sides of which are either convex curves or straight andextend inward toward the axis of rotation of the core to substantiallymeet at the bottom of the groove. The groove completely encircles thecore in a plane perpendicular to the axis of rotation. The depth of thegroove, i.e., the distance that the groove penetrates into the core, maybe from approximately 0.03 inch (0.0762 cm.) to slightly less than thethickness of the core, or in the case of a solid cylindrical bobbin, toapproximately 0.125 inch (0.3175 cm.) less than its rathe core,

the core,

dius. Preferably, the depth of the groove is approximately 0.078 inch(0.1981 cm.) in a core of approximately 2-inches (5.08 cm.) outsidediameter and approximately 1.66-inches (4.22 cm.) inside diameter. Theopening of the groove, i.e., the length of a straight line connectingeach point of intersection (or tangency, if the groove edges arerounded) of the groove sides with outer core surface adjacent to saidsides may be of any length customarily used in the art to accommodatethe diameter of the yarn to be used. Preferably, if the groove edges arenot rounded the opening is approximately 0.015 to 0.1 inch (0.0381 to0.254 cm.) when dealing with ISO-denier, 34-filament polyethyleneterephthalate yarns. Greater groove openings are used when the edges ofthe groove are rounded.

The geometry of the yarn trap, i.e., the structure designed to catch theyarn in accordance with the present invention, is essential to theinvention. The yarn trap substantially comprises a protuberanceextending from at least one side of the groove in which it is formed. Asimple yarn trap suitable for the practice of this invention is shown inFIGURE 4. The protuberance, which may be of any shape, must be situatedbetween the bottom of the groove and a point lying approximately of theshortest distance from said bottom to a straight line connecting thegroove edges at the groove opening. Further, the protuberance mustsubstantially touch the op posite groove side. Preferably, when usingthe abovespecified yarns, the protuberance is situated approximately inthe lower /5 of the depth of the groove, and the face of theprotuberance actually touches the opposite groove side. It is preferredthat the protuberance be placed in the groove side which is farther fromthe core end nearer to the groove.

Surprisingly, it has been found that the width of the protuberance,measured along the length of the groove, should be less than 0.25 timesthe circumference of the core or bobbin. Preferably, the width of theprotuberance is approximately 0.017 times the circumference of the core.

Subject to the above limitations in the geometrical design of the yarntrap, many modifications will be apparent to those skilled in the art.The stnuctural modifications envisioned will primarily be the result ofthe methods used to form the protuberance. For example, referring toFIGURE 3, the surface 8, which is an inward depression in the outer faceof the core and in the groove side containing the protuberance, resultsfrom a convenient process whereby the edge of the groove is stamped orpressed or otherwise depressed in order to form the protuberance.Further, FIGURE 5 shows the depression in the outer face of the coreoccurring in both groove sides. All of these structures are intended tolie within the spirit and scope of the present specification. It ispreferable, however, that the depressed surface be located entirely inthe groove side containing the protuberance.

In using the core for winding a package, the yarn is first caused topass through the nozzle of a socker gun and is placed in a position tobe engaged by a traverse means. As soon as the yarn is so engaged, it isplaced, by moving the sucker gun, so as to come in contact with the newcore at a wrap angle of from approximately 90 to 180. The direction ofyarn motion is opposite the direction of peripheral rotation of thecore. The yarn is quickly caused to come into contact with the groove ofthe core. As the core rotates, the yarn is engaged by at least one ofthe traps and is subsequently broken. The yarn is then guided bytraverse means to be helically wound around the core. The traverse meansis preferably adjusted so that the edge of the package closest to thegroove will be an appreciable distance from the groove, preferably 0.25inch (0.635 cm.). Thus, the Winding forms a traverse tail as describedabove.

Usually only a portion of the filaments of the yarn are caught in thefirst trap the yarn meets, and all of the filaments are caught in thesecond trap. Thus it is essential to the invention that there be morethan one trap in the core. Preferably, the core contains six traps.

Any synthetic, man-made, or natural fiber may be used in the practice ofthis invention. Continuous-filament yarn as Well as staple-spun yarn mayeffectively be used.

The following example will illustrate one way of practicing theinvention, although it is not intended to limit its scope.

Example A spirally wound, cylindrical kraft-paper textile tube ll-inches(27.94 cm.) long and having an inside diameter of 2.015 inches (5.118cm.) and an outside diameter of 2.327 inches (5.911 cm.) is grooved witha knife. The single groove is approximately 0.375 inch (0.953 cm.) fromone end of the tube. The groove is 0.0781 inch (0.1984 cm.) deep and hasrounded edges (approximately 0.0312-inch (0.0792 cm.) radius). Thegroove opening is approximately 0.0665 inch (0.1639 cm.).

Six yarn traps (two series of 3 traps each, the middle trap of eachseries being 0.375 inch (0.8525 cm.) from the traps adjacent to it, theangular distance from the middle trap of one series to the middle trapof the other being 180) are formed in the core by punching the grooveedge which is farthest from the near end of the core. The punch has a0.125-inch (0.3175 cm.) diameter flat circular face. The core having thetraps therein substantially resembles the illustration in FIGURE 1. Thedepth of each depression in the core surface made by the punch isapproximately 0.047 inch (0.119 cm.) and the crosssection of the traps,thus formed, resembles the illustration of FIGURE 3. A portion of theface of each protuberance of the traps touches the opposite groove side.

Twenty cores are constructed as above and evaluated for string-upefiiciency. (String-up efliciency is defined as the percent successfulstring-up attempts versus the number of total attempts, unsuccessfulattempts versus the number of total attempts, unsuccessful attemptsbeing those in which the yarn breaks without initial package formation,or attempts in which package build-up cannot be initiated at all.) Thetubes are mounted to be surface driven by means of drive rolls. The yarnused for this example is ISO-denier, 34-filament polyethyleneterephthalate having a tenacity of 4.5 grams per denier. The peripheralspeed of the tubes is approximately 3000 yards per minute (2743.2m./min.). The yarn is taken into a sucker gun and brought into contactwith the core as described above at a wrap angle of approximatelyString-up efliciency is greater than 99%.

For comparison, a series of tubes constructed as described above withthe exception that no yarn traps are present therein, is tested forstring-up efiiciency. An

identical yarn is used and all other procedures are followed. String-upefficiency is approximately 5%.

Thus, in the process of winding high-denier, highstrength yarns, threadsand the like, the tremendous advantage of the practical, eificient andeconomical enablement of high-speed operation is realized by the use ofcores or bobbins embodying the improved features of the presentinvention.

Since many different embodiments of the invention may be made withoutdeparting from the spirit and scope thereof, it is to be understood thatthe invention is not limited by the specific illustrations except to theextent defined in the following claims.

I claim:

1. For use in winding yarn packages at high speed, a textile core havinga cylindrical body for supporting the yarn, a circumferential groovenear. one end of the body for engaging yarn when starting to wind apackage, said groove being a generally V-shaped notch of substantiallyuniform depth in the exterior surface of the body and aligned in a planeperpendicular to the cylinder axis of the body, the opposite sides ofthe groove converging to meet in an acute angle at the bottom of thegroove, and a plurality of yarn traps along the groove for catching yarnin the groove and for breaking off the lead end of the yarn to start apackage, each of said traps comprising a protuberance on one side of thegroove which substantially touches the opposite side of the groove, issituated in the lower A of the depth of the groove, and has a widthmeasured along the groove of less than 0.25 times the circumference ofthe body.

2. A textile core as defined in claim 1 wherein the yarn trap comprisesa portion above said protuberance which is a circular depression in thesurface of the cylindrical body and has a width approximately 0.017times the circumference of the body.

3. A textile core as defined in claim 1 wherein said UNITED STATESPATENTS 1,924,510 8/1933 Parks 242-125.2 2,258,900 10/1941 Little et a1242-125.1 2,262,665 11/ 1941 Cavanaugh 242125.1 3,103,305 9/1963Heatherly 225-6 FRANK I. COHEN, Primary Examiner.

G. F. MAUTZ, Assistant Examiner.

1. FOR USE IN WINDING YARN PACKAGES AT HIGH SPEED, A TEXTILE CORE HAVINGA CYLINDRICAL BODY FOR SUPPORTING THE YARN, A CIRCUMFERENTIAL GROOVENEAR ONE END OF THE BODY FOR ENGAGING YARN WHEN STARTING TO WIND APACKAGE, SAID GROOVE BEING A GENERALLY V-SHAPED NOTCH OF SUBSTANTIALLYUNIFORM DEPTH IN THE EXTERIOR SURFACE OF THE BODY AND ALIGNED IN A PLANEPERPENDICULAR TO THE CYLINDER AXIS OF THE BODY, THE OPPOSITE SIDES OFTHE GROOVE CONVERGING TO MEET IN AN ACUTE ANGLE AT THE BOTTOM OF THEGROOVE, AND A PLURALITY OF YARN TRAPS ALONG THE GROOVE FOR CATCHING YARNIN THE GROOVE AND FOR BREAKING OFF THE LEAD END OF THE YARN TO START APACKAGE, EACH OF SAID TRAPS COMPRISING A PROTUBERANCE ON ONE SIDE OF THEGROOVE WHICH SUBSTANTIALLY TOUCHES THE OPPOSITE SIDE OF THE GROOVE, ISSITUATED IN THE LOWER 3/4 OF THE DEPTH OF GROOVE, AND HAS A WIDTHMEASURED ALONG THE GROOVE OF LESS THAN 0.25 TIMES THE CIRCUMFERENCE OFTHE BODY.